Aerosol-generating article comprising a mouth-end cooling element

ABSTRACT

An aerosol-generating article is provided, including: a rod of aerosol-generating substrate including an aerosol former, the substrate having an aerosol former content of greater than 10 percent on a dry weight basis; a hollow tubular support element positioned immediately downstream of the rod; an aerosol-cooling element downstream of the support element, the aerosol-cooling element extending all the way to a downstream end of the article, the aerosol-cooling element including a hollow tubular segment having a transverse wall at a location between an upstream end and a downstream end of the hollow tubular segment, such that it defines a first cavity upstream of the transverse wall and a second cavity downstream of the transverse wall, and the transverse wall including one or more openings establishing a fluid communication between the first cavity and the second cavity.

The present invention relates to an aerosol generating article comprising an aerosol-generating substrate and adapted to produce an inhalable aerosol upon heating.

Aerosol-generating articles in which an aerosol-generating substrate, such as a tobacco-containing substrate, is heated rather than combusted, are known in the art. Typically in such heated smoking articles, an aerosol is generated by the transfer of heat from a heat source to a physically separate aerosol-generating substrate or material, which may be located in contact with, within, around, or downstream of the heat source. During use of the aerosol-generating article, volatile compounds are released from the aerosol-generating substrate by heat transfer from the heat source and are entrained in air drawn through the aerosol-generating article. As the released compounds cool, they condense to form an aerosol.

A number of prior art documents disclose aerosol-generating devices for consuming aerosol-generating articles. Such devices include, for example, electrically heated aerosol-generating devices in which an aerosol is generated by the transfer of heat from one or more electrical heater elements of the aerosol-generating device to the aerosol-generating substrate of a heated aerosol-generating article.

Substrates for heated aerosol-generating articles have, in the past, typically been produced using randomly oriented shreds, strands, or strips of tobacco material. More recently, alternative substrates for aerosol-generating articles to be heated rather than combusted have been disclosed, such as rods formed from gathered sheets of tobacco material. By way of example, the rods disclosed in international patent application WO-A-2012/164009 have a longitudinal porosity that allows air to be drawn through the rods. As a further alternative, international patent application WO-A-2011/101164 discloses rods for heated aerosol-generating articles formed from strands of homogenised tobacco material, which may be formed by casting, rolling, calendering or extruding a mixture comprising particulate tobacco and at least one aerosol former to form a sheet of homogenised tobacco material. In another embodiment, the rods of WO-A-2011/101164 may be formed from strands of homogenised tobacco material obtained by extruding a mixture comprising particulate tobacco and at least one aerosol former to form continuous lengths of homogenised tobacco material.

Substrates for heated aerosol-generating articles typically further comprise an aerosol former, that is, a compound or mixture of compounds that, in use, facilitates formation of the aerosol and that preferably is substantially resistant to thermal degradation at the operating temperature of the aerosol-generating article. Examples of suitable aerosol-formers include, but are not limited to: polyhydric alcohols, such as propylene glycol, triethylene glycol, 1,3-butanediol and glycerin; esters of polyhydric alcohols, such as glycerol mono-, di- or triacetate; and aliphatic esters of mono-, di- or polycarboxylic acids, such as dimethyl dodecanedioate and dimethyl tetradecanedioate.

It is also common to include in an aerosol-generating article for producing an inhalable aerosol upon heating one or more additional elements that are assembled with the substrate in a same wrapper. Examples of such additional elements include a mouthpiece filtration segment, a support element adapted to impart structural strength to the aerosol-generating article.

It has also been proposed to include in an aerosol-generating article for producing an inhalable aerosol upon heating a cooling element adapted to favour cooling of the aerosol prior to reaching the mouthpiece. By way of example, WO 2013/120565 discloses an aerosol-generating article an aerosol-forming substrate and an aerosol-cooling element located downstream from the aerosol-forming substrate within the rod. In an embodiment, the aerosol-cooling element comprises a crimped sheet of polylactic acid (PLA) that has been gathered to define a plurality of longitudinally extending channels. As the stream of aerosol is drawn through the aerosol-cooling element, heat may be transferred from the aerosol to the sheet of PLA.

When an aerosol-generating article of the type described above is used under particularly hot and humid weather conditions, such as those frequently encountered in countries characterised by a tropical climate, the temperature reached by the mouthpiece of the article may be as high as in the range from 42 degrees Celsius to 45 degrees Celsius. These temperatures may be associated with a feeling of discomfort or mild pain for some consumers, as sensitive tissues such as lips, mouth, tongue and mucosae in general may come into direct contact with a surface of the mouthpiece during use. Without wishing to be bound by theory, this is understood to be because warm thermoreceptors, which respond to increases in skin temperature, are most responsive at approximately 45 degrees Celsius. By contrast, when the temperature of the skin is from about 30 degrees Celsius to about 36 degrees Celsius, warm thermoreceptors are spontaneously active, but there is generally no awareness of warmth (neutral thermal region). In addition, the skin also contains thermally sensitive receptors known as thermal nociceptors that lead to a painful sensation when the temperature of the skin rises above 45 degrees Celsius. This is because nociceptors responsive to temperature are meant to signal to the central nervous system that tissue damage may be imminent and that the affected body part should be promptly withdrawn from the heat source.

Thus, it would be desirable to provide a novel and improved aerosol generating article adapted to optimise cooling of the aerosol being delivered to the consumer. It would also be desirable to provide a novel and improved aerosol-generating article adapted to optimise cooling of surfaces of the mouth end of the article that may come into contact with sensitive tissues of the consumer during use. At the same time, it would be desirable to provide one such aerosol-generating article that can be manufactured efficiently and at high speed without requiring major modifications of existing equipment and apparatus.

Thus, the present invention relates to an aerosol-generating article for producing an aerosol upon heating. The aerosol-generating article may comprise a rod of aerosol-generating substrate. The aerosol-generating article may comprise a hollow tubular support element, which may be positioned immediately downstream of the rod of aerosol-generating substrate. The aerosol-generating article may comprise an aerosol-cooling element downstream of the hollow tubular support element. The aerosol-cooling element may extend all the way to a downstream end of the aerosol-generating article, and may comprises a hollow tubular segment having a transverse wall at a location between an upstream end and a downstream end of the hollow tubular segment. Thus, the hollow tubular segment may define a first cavity upstream of the transverse wall and a second cavity downstream of the transverse wall. The transverse wall may comprise one or more openings establishing a fluid communication between the first cavity and the second cavity.

According to an aspect of the present invention, there is provided an aerosol-generating article for producing an aerosol upon heating, the aerosol-generating article comprising: a rod of aerosol-generating substrate; a hollow tubular support element positioned immediately downstream of the rod of aerosol-generating substrate; and an aerosol-cooling element downstream of the hollow tubular support element. The aerosol-cooling element extends all the way to a downstream end of the aerosol-generating article. Further, the aerosol-cooling element comprises a hollow tubular segment having a transverse wall at a location between an upstream end and a downstream end of the hollow tubular segment, such that the hollow tubular segment defines a first cavity upstream of the transverse wall and a second cavity downstream of the transverse wall. In addition, the transverse wall comprises one or more openings establishing a fluid communication between the first cavity and the second cavity.

According to another aspect of the present invention, there is provided an aerosol-generating system comprising an aerosol generating article as described above and an electrically operated aerosol generating device comprising a heating element and an elongate heating chamber configured to receive the aerosol generating article so that the rod of aerosol-generating substrate is heated in the heating chamber.

It will be appreciated that any features described with reference to one aspect of the present invention are equally applicable to any other aspect of the invention.

The term “aerosol generating article” is used herein with reference to the invention to describe an article wherein an aerosol generating substrate is heated to produce and deliver an aerosol to a consumer. As used herein, the term “aerosol generating substrate” denotes a substrate capable of releasing volatile compounds upon heating to generate an aerosol.

A conventional cigarette is lit when a user applies a flame to one end of the cigarette and draws air through the other end. The localised heat provided by the flame and the oxygen in the air drawn through the cigarette causes the end of the cigarette to ignite, and the resulting combustion generates an inhalable smoke. By contrast, in heated aerosol generating articles, an aerosol is generated by heating a flavour generating substrate, such as tobacco. Known heated aerosol generating articles include, for example, electrically heated aerosol generating articles and aerosol generating articles in which an aerosol is generated by the transfer of heat from a combustible fuel element or heat source to a physically separate aerosol forming material. For example, aerosol generating articles according to the invention find particular application in aerosol generating systems comprising an electrically heated aerosol generating device having an internal heater blade which is adapted to be inserted into the rod of aerosol generating substrate. Aerosol generating articles of this type are described in the prior art, for example, in EP 0822670.

As used herein, the term “aerosol generating device” refers to a device comprising a heater element that interacts with the aerosol generating substrate of the aerosol generating article to generate an aerosol.

During use, volatile compounds are released from the aerosol-generating substrate by heat transfer and entrained in air drawn through the aerosol generating article. As the released compounds cool they condense to form an aerosol that is inhaled by the consumer.

As used herein, the term “tubular element” denotes a elongate element defining a lumen or airflow passage along a longitudinal axis thereof. In the context of the present specification, the term “tubular” is intended to encompass any tubular element having a substantially cylindrical cross-section which defines at least one airflow conduit establishing fluid communication between an upstream end of the tubular element and a downstream end of the tubular element. As used herein with reference to the present invention, the term “hollow” is used to describe a tubular element that defines an internal empty space, such as a chamber or cavity.

As used herein, the term “longitudinal” refers to the direction corresponding to the main longitudinal axis of the aerosol-generating article, which extends between the upstream and downstream ends of the aerosol-generating article. As used herein, the terms “upstream” and “downstream” describe the relative positions of elements, or portions of elements, of the aerosol-generating article in relation to the direction in which the aerosol is transported through the aerosol-generating article during use. During use, air is drawn through the aerosol-generating article in the longitudinal direction. The term “transverse” refers to the direction that is perpendicular to the longitudinal axis. Any reference to the “cross-section” of the aerosol-generating article or a component of the aerosol-generating article refers to the transverse cross-section unless stated otherwise.

The term “length” denotes the maximum dimension of a component of the aerosol-generating article in the longitudinal direction. For example, it may be used to denote the dimension of the rod or of the tubular element in the longitudinal direction. In particular, in the context of the present invention, the term “length of the tubular element” is used to denote the maximum distance between the upstream and downstream ends of the tubular element. Further, the term “length of an internal cavity of the tubular element” is used to denote the maximum distance between the transverse wall and a corresponding one of the upstream and downstream ends of the tubular element.

For example, the length of the upstream cavity of the tubular element may be assessed as the maximum distance between a transverse plane defined by the upstream end surface of the peripheral wall of the tubular support element and a transverse plane defined by the location of the transverse wall along the length of the tubular support element (that is, a mid-plane of the transverse wall).

The term “thickness of a peripheral wall of the tubular element” is used in the present specification to denote the minimum distance measured between the outer surface and the inner surface of a wall of a tubular element. In practice, the distance at a given location is measured along a direction locally substantially perpendicular to opposite sides of the wall of the tubular element. For a substantially cylindrical tubular element, that is, a tubular element having a substantially circular cross-section, the thickness of the peripheral wall is assessed as the distance between the outer surface and the inner surface of the peripheral wall measured along a substantially radial direction of the tubular element.

The expression “air-impervious material” is used throughout this specification to mean a material not allowing the passage of fluids, particularly air and smoke, through interstices or pores in the material. If the tubular support element is formed of a material impervious to air and aerosol particles, air and aerosol particles drawn through the support element are forced to flow through the airflow conduit, but cannot flow across a wall of the support element.

By contrast, the term “porous” is used herein to refer to a material that provides a plurality of pores or openings that allow the passage of air through the material.

The term “equivalent diameter of an opening” is used herein to denote the diameter of a circular opening having the same cross-sectional surface area as the opening.

As used in the present specification, the term “homogenised tobacco material” encompasses any tobacco material formed by the agglomeration of particles of tobacco material. Sheets or webs of homogenised tobacco material are formed by agglomerating particulate tobacco obtained by grinding or otherwise powdering of one or both of tobacco leaf lamina and tobacco leaf stems. In addition, homogenised tobacco material may comprise a minor quantity of one or more of tobacco dust, tobacco fines, and other particulate tobacco by-products formed during the treating, handling and shipping of tobacco. The sheets of homogenised tobacco material may be produced by casting, extrusion, paper making processes or other any other suitable processes known in the art.

As briefly described above, an aerosol generating article in accordance with the present invention incorporates a rod of aerosol-generating substrate and a hollow tubular support element positioned immediately downstream of the rod of aerosol-generating substrate. Further, the aerosol-generating article of the invention comprises an aerosol-cooling element downstream of the hollow tubular support element.

In contrast with existing aerosol-generating articles, in articles in accordance with the present invention the aerosol-cooling element extends all the way to a downstream end of the aerosol-generating article. In other words, the aerosol-cooling element defines the mouth-end portion of the article and, during use, may be drawn on by a consumer. Further, the aerosol-cooling element comprises a hollow tubular segment having a transverse wall at an intermediate location along its length. As such, an internal volume of the hollow tubular segment is divided into a first cavity upstream and a second cavity, the cavities being arranged upstream and downstream of the transverse wall, respectively. One or more openings are formed through the transverse wall. The one or more openings establish a fluid communication between the cavities.

In aerosol-generating articles in accordance with the present invention, the aerosol-cooling element is adapted to lower the temperature of the aerosol flowing through the article, whilst at the same time homogenising the flow of aerosol and finely controlling how the aerosol flow is delivered to the consumer's mouth.

In more detail, it has been found that the structure and features of the aerosol-cooling element are such as to consistently lower the temperature of the gaseous flow in the article below the threshold values which may be associated with a sensation of discomfort or pain for the consumer. Without wishing to be bound by theory, it is understood that in aerosol-generating articles in accordance with the invention, heat from the aerosol flowing through the article is conveniently dissipated as the material of the aerosol-cooling element is heated by conduction and convection. At the same time, as the flow of aerosol is concentrated through the one or more openings in the transverse wall before being distributed more broadly across the cross-section of the downstream cavity, overheating of the outer surfaces of the article that may come into contact with the consumer's lips during use is advantageously prevented, even when the article is used under particularly hot and humid weather conditions. In addition, as the transverse wall partially obstructs the flow and directs the air and airborne volatilised aerosol species through the opening or openings in the transverse wall, turbulence is increased and so heat transfer from the gaseous flow to the transverse wall is expected to be favoured over heat transfer from the gaseous flow to the peripheral wall.

Further, aerosol-generating articles in accordance with the present invention may be manufactured in a continuous process, and their production may conveniently be implemented at high speed and incorporated into existing production lines for the manufacture of heated aerosol-generating articles without requiring extensive modifications of the manufacturing equipment.

Aerosol generating articles in accordance with the present invention comprise an aerosol generating substrate, which may be provided in the form of a rod circumscribed by a wrapper.

The rod of aerosol generating substrate preferably has an external diameter that is approximately equal to the external diameter of the aerosol generating article.

Preferably, the rod of aerosol generating substrate has an external diameter of at least 5 millimetres. The rod of aerosol generating substrate may have an external diameter of between about 5 millimetres and about 12 millimetres, for example of between about 5 millimetres and about 10 millimetres or of between about 5 millimetres and about 8 millimetres or of between about 6 millimetres and about 12 millimetres or of between about 6 millimetres and 10 millimetres or of between about 6 millimetres and about 8 millimetres. In a preferred embodiment, the rod of aerosol generating substrate has an external diameter of 7.2 millimetres.

The rod of aerosol generating substrate may have a length of between about 5 millimetres and about 100 mm. Preferably, the rod of aerosol generating substrate has a length of at least about 5 millimetres, more preferably at least about 7 millimetres. In addition, or as an alternative, the rod of aerosol generating substrate preferably has a length of less than about 100 millimetres, more preferably less than about 80 millimetres, even more preferably less than about 65 millimetres, most preferably less than or equal to about 50 millimetres. In particularly preferred embodiments, the rod of aerosol generating substrate has a length of less than or equal to about 35 millimetres, more preferably less than or equal to 25 millimetres, even more preferably less than or equal to about 20 millimetres. In one embodiment, the rod of aerosol generating substrate may have a length of about 10 millimetres. In a preferred embodiment, the rod of aerosol generating substrate has a length of about 12 millimetres.

In some embodiments, the rod of aerosol generating substrate has a length of from about 5 millimetres to about 80 millimetres or from about 5 millimetres to about 65 millimetres or from about 5 millimetres to about 50 millimetres. In other embodiments, the rod of aerosol generating substrate has a length of from about 7 millimetres to about 100 millimetres or from about 7 millimetres to about 80 millimetres or from about 7 millimetres to about 65 millimetres or from about 7 millimetres to about 50 millimetres. In further embodiments, the rod of aerosol generating substrate has a length of from about 10 millimetres to about 100 millimetres or from about 10 millimetres to about 80 millimetres or from about 10 millimetres to about 65 millimetres or from about 10 millimetres to about 50 millimetres.

Preferably, the rod of aerosol generating substrate has a substantially uniform cross-section along the length of the rod. Particularly preferably, the rod of aerosol generating substrate has a substantially circular cross-section.

In preferred embodiments, the aerosol-generating substrate comprises one or more gathered sheets of homogenised tobacco material. Preferably the one or more sheets of homogenised tobacco material are textured. As used herein, the term ‘textured sheet’ denotes a sheet that has been crimped, embossed, debossed, perforated or otherwise deformed. Textured sheets of homogenised tobacco material for use in the invention may comprise a plurality of spaced-apart indentations, protrusions, perforations or a combination thereof. According to a particularly preferred embodiment of the invention, the rod of aerosol-generating substrate comprises a gathered crimped sheet of homogenised tobacco material circumscribed by a wrapper.

As used herein, the term ‘crimped sheet’ is intended to be synonymous with the term ‘creped sheet’ and denotes a sheet having a plurality of substantially parallel ridges or corrugations. Preferably, the crimped sheet of homogenised tobacco material has a plurality of ridges or corrugations substantially parallel to the cylindrical axis of the rod according to the invention. This advantageously facilitates gathering of the crimped sheet of homogenised tobacco material to form the rod. However, it will be appreciated that crimped sheets of homogenised tobacco material for use in the invention may alternatively or in addition have a plurality of substantially parallel ridges or corrugations disposed at an acute or obtuse angle to the cylindrical axis of the rod. In certain embodiments, sheets of homogenised tobacco material for use in the rod of the article of the invention may be substantially evenly textured over substantially their entire surface. For example, crimped sheets of homogenised tobacco material for use in the manufacture of a rod for use in an aerosol-generating article in accordance with the invention may comprise a plurality of substantially parallel ridges or corrugations that are substantially evenly spaced-apart across the width of the sheet.

Sheets or webs of homogenised tobacco material for use in the invention may have a tobacco content of at least about 40 percent by weight on a dry weight basis, more preferably of at least about 60 percent by weight on a dry weight basis, more preferably or at least about 70 percent by weight on a dry basis and most preferably at least about 90 percent by weight on a dry weight basis.

Sheets or webs of homogenised tobacco material for use in the aerosol-generating substrate may comprise one or more intrinsic binders, that is tobacco endogenous binders, one or more extrinsic binders, that is tobacco exogenous binders, or a combination thereof to help agglomerate the particulate tobacco. Alternatively, or in addition, sheets of homogenised tobacco material for use in the aerosol-generating substrate may comprise other additives including, but not limited to, tobacco and non-tobacco fibres, aerosol-formers, humectants, plasticisers, flavourants, fillers, aqueous and non-aqueous solvents and combinations thereof.

Suitable extrinsic binders for inclusion in sheets or webs of homogenised tobacco material for use in the aerosol-generating substrate are known in the art and include, but are not limited to: gums such as, for example, guar gum, xanthan gum, arabic gum and locust bean gum; cellulosic binders such as, for example, hydroxypropyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, methyl cellulose and ethyl cellulose; polysaccharides such as, for example, starches, organic acids, such as alginic acid, conjugate base salts of organic acids, such as sodium-alginate, agar and pectins; and combinations thereof.

Suitable non-tobacco fibres for inclusion in sheets or webs of homogenised tobacco material for use in the aerosol-generating substrate are known in the art and include, but are not limited to: cellulose fibres; soft-wood fibres; hard-wood fibres; jute fibres and combinations thereof. Prior to inclusion in sheets of homogenised tobacco material for use in the aerosol-generating substrate, non-tobacco fibres may be treated by suitable processes known in the art including, but not limited to: mechanical pulping; refining; chemical pulping; bleaching; sulphate pulping; and combinations thereof.

Preferably, the sheets or webs of homogenised tobacco material comprise an aerosol former. As used herein, the term “aerosol former” describes any suitable known compound or mixture of compounds that, in use, facilitates formation of an aerosol and that is substantially resistant to thermal degradation at the operating temperature of the aerosol-generating article.

Suitable aerosol-formers are known in the art and include, but are not limited to: polyhydric alcohols, such as propylene glycol, triethylene glycol, 1,3-butanediol and glycerine; esters of polyhydric alcohols, such as glycerol mono-, di- or triacetate; and aliphatic esters of mono-, di- or polycarboxylic acids, such as dimethyl dodecanedioate and dimethyl tetradecanedioate.

Preferred aerosol formers are polyhydric alcohols or mixtures thereof, such as propylene glycol, triethylene glycol, 1,3-butanediol and, most preferred, glycerine.

The sheets or webs of homogenised tobacco material may comprise a single aerosol former. Alternatively, the sheets or webs of homogenised tobacco material may comprise a combination of two or more aerosol formers.

The sheets or webs of homogenised tobacco material have an aerosol former content of greater than 10 percent on a dry weight basis. Preferably, the sheets or webs of homogenised tobacco material have an aerosol former content of greater than 12 percent on a dry weight basis. More preferably, the sheets or webs of homogenised tobacco material have an aerosol former content of greater than 14 percent on a dry weight basis. Even more preferably the sheets or webs of homogenised tobacco material have an aerosol former content of greater than 16 percent on a dry weight basis.

The sheets of homogenised tobacco material may have an aerosol former content of between approximately 10 percent and approximately 30 percent on a dry weight basis. Preferably, the sheets or webs of homogenised tobacco material have an aerosol former content of less than 25 percent on a dry weight basis.

In a preferred embodiment, the sheets of homogenised tobacco material have an aerosol former content of approximately 20 percent on a dry weight basis.

Sheets or webs of homogenised tobacco for use in the aerosol-generating article of the present invention may be made by methods known in the art, for example the methods disclosed in International patent application WO-A-2012/164009 A2. In a preferred embodiment, sheets of homogenised tobacco material for use in the aerosol-generating article are formed from a slurry comprising particulate tobacco, guar gum, cellulose fibres and glycerine by a casting process.

Alternative arrangements of homogenised tobacco material in a rod for use in an aerosol-generating article will be known to the skilled person and may include a plurality of stacked sheets of homogenised tobacco material, a plurality of elongate tubular elements formed by winding strips of homogenised tobacco material about their longitudinal axes, etc.

As a further alternative, the rod of aerosol-generating substrate may comprise a non-tobacco-based, nicotine-bearing material, such as a sheet of sorbent non-tobacco material loaded with nicotine (for example, in the form of a nicotine salt) and an aerosol-former. Examples of such rods are described in the international application WO-A-2015/052652. In addition, or as an alternative, the rod of aerosol-generating substrate may comprise a non-tobacco plant material, such as an aromatic non-tobacco plant material.

In the rod of aerosol-generating substrate of articles in accordance with the invention, the aerosol-generating substrate is preferably circumscribed by a wrapper. The wrapper may be formed of a porous or non-porous sheet material. The wrapper may be formed of any suitable material or combination of materials. Preferably, the wrapper is a paper wrapper.

In aerosol-generating articles in accordance with the present invention, a tubular support element is provided at a location downstream of the rod of aerosol-generating substrate. The tubular support element comprises a cylindrical peripheral wall and defines an airflow conduit extending longitudinally from an upstream end of the tubular support element to a downstream end of the tubular support element. Thus, the tubular support element establishes a fluid communication between the rod of aerosol-generating substrate and the one or more components of the article located further downstream.

In more detail, the tubular support element is longitudinally aligned with the rod, and is arranged immediately downstream of the rod. In the context of the present invention, the expression “immediately downstream of the rod” means that the tubular support element and the rod are in contact with one another or very close to one another, such that when the article is received for use in an aerosol-generating device adapted to heat the aerosol-generating substrate (for example, one including a heating element that is inserted into the rod) the tubular support element effectively provides support for the rod, with little to no deformation of the aerosol-generating article, or with little to no displacement of the rod, or both. Thus, in practice, as used herein with reference to the present invention, the expression “immediately downstream of the rod” is used to indicate that a minimum longitudinal distance between a downstream end surface of the rod and an upstream end surface of the peripheral wall of the tubular support element is less than 1 millimetre, preferably less than 0.5 millimetres, even more preferably less than 0.25 millimetres. In particularly preferred embodiments, an upstream end surface of the peripheral wall of the tubular support element directly contacts the downstream end surface of the rod of aerosol-generating substrate.

Thus, the tubular support element may effectively maintain the rod of aerosol-generating substrate at a predetermined distance from a downstream end of the aerosol-generating article. In addition, the tubular support element imparts structural strength to the aerosol-generating article, such that it can easily be handled by the consumer and that it may conveniently be inserted into an aerosol-generating device for use.

The tubular support element may be made of a porous material or of an air-impervious material. Suitable examples of porous material include, but are not limited to, cellulose acetate as well as a number of other porous polymeric materials, which will be known to the skilled person.

Suitable examples of air-impervious materials include, but are not limited to, non-porous polymeric materials, with particular preference for bioplastics.

In a preferred embodiment, the tubular support element is a hollow tube of cellulose acetate.

During use, a thermal gradient is established along the airflow conduit of the tubular support element. In practice, a temperature differential is provided, such that a temperature of the volatilised aerosol components entering the tubular support element at the downstream end of the rod of aerosol-generating substrate is generally greater than a temperature of the volatilised aerosol components exiting the tubular support element at the downstream end of the tubular support element. However, this is generally not enough to sufficiently cool the volatilised aerosol components.

A thickness of the cylindrical peripheral wall of the hollow tubular support element is preferably less than or equal to 2 millimetres. More preferably, a thickness of the cylindrical peripheral wall is less than or equal to 1.5 millimetres. Even more preferably, a thickness of the cylindrical peripheral wall is less than or equal to 1 millimetre.

A thickness of the cylindrical peripheral wall of the hollow tubular support element is at least 0.2 millimetres. More preferably, a thickness of the cylindrical peripheral wall is at least 0.4 millimetres. Even more preferably, a thickness of the cylindrical peripheral wall is at least 0.6 millimetres.

In some embodiments, a thickness of the cylindrical peripheral wall of the hollow tubular support element is from about 0.2 millimetres to about 2 millimetres or from about 0.2 millimetres to about 1.5 millimetres or from about 0.2 millimetres to about 1 millimetre. In other embodiments, a thickness of the cylindrical peripheral wall of the hollow tubular support element is from about 0.4 millimetres to about 2 millimetres or from about 0.4 millimetres to about 1.5 millimetres or from about 0.4 millimetres to about 1 millimetre. In further embodiments, a thickness of the cylindrical peripheral wall of the hollow tubular support element is from about 0.6 millimetres to about 2 millimetres or from about 0.6 millimetres to about 1.5 millimetres or from about 0.6 millimetres to about 1 millimetre.

In some preferred embodiments, a thickness of the cylindrical peripheral wall of the hollow tubular support element is from about 0.2 millimetres to about 2 millimetres, more preferably from about 0.4 millimetres to about 1.5 millimetres, even more preferably from about 0.6 millimetres to about 1 millimetre.

Thus, at the upstream end, the cylindrical peripheral wall presents an end surface adapted to abut a peripheral portion of the rod of aerosol-generating substrate. In some embodiments, the upstream end surface of the peripheral wall may have a substantially flat profile. Thus, it may contact substantially in its entirety the downstream end surface of the rod. In alternative embodiments, the upstream end surface of the peripheral wall has a non-flat profile, for example a slanted profile or a curved profile, such that the peripheral wall contacts the rod only at its outermost peripheral edge, whereas some spacing is provided between the downstream end surface of the rod and the end surface of the peripheral wall at the inner periphery of the peripheral wall.

Preferably, a length of the hollow tubular support element is at least about 10 millimetres. More preferably, a length of the hollow tubular support element is at least about 15 millimetres. Even more preferably, a length of the hollow tubular support element is at least about 20 millimetres.

A length of the hollow tubular support element is preferably less than or equal to about 60 millimetres. More preferably, a length of the hollow tubular support element is less than or equal to about 50 millimetres. Even more preferably, a length of the hollow tubular support element is less than or equal to about 40 millimetres.

In some embodiments, a length of the hollow tubular support element is from about 10 millimetres to about 60 millimetres or from about 10 millimetres to about 50 millimetres or from about 10 millimetres to about 40 millimetres. In other embodiments, a length of the hollow tubular support element is from about 15 millimetres to about 60 millimetres or from about 15 millimetres to about 50 millimetres or from about 15 millimetres to about 40 millimetres. In further embodiments, a length of the hollow tubular support element is from about 20 millimetres to about 60 millimetres or from about 20 millimetres to about 50 millimetres or from about 20 millimetres to about 40 millimetres.

In some preferred embodiments, a length of the hollow tubular support element is from about 10 millimetres to about 60 millimetres, more preferably from about 15 millimetres to about 50, even more preferably from about 20 millimetres to about 40 millimetres.

As described briefly above, an aerosol-generating article in accordance with the present invention comprises an aerosol-cooling element longitudinally aligned with the rod and the hollow tubular support element and positioned downstream of the hollow tubular support element.

In some embodiments, the aerosol-cooling element is positioned immediately downstream of the hollow tubular support element. As used herein with reference to the invention, the expression “immediately downstream of the hollow tubular support element” means that the aerosol-cooling element are in contact with one another or very close to one another. In practice, the expression “immediately downstream of the hollow tubular support element” is used to indicate that minimum longitudinal distance between a downstream end surface of the hollow tubular support element and an upstream end surface of the peripheral wall of the aerosol-cooling element is less than 1 millimetre, preferably less than 0.5 millimetres, even more preferably less than 0.25 millimetres. In particularly preferred embodiments, an upstream end surface of the aerosol-cooling element directly contacts the downstream end surface of the peripheral wall of the hollow tubular support element.

In other embodiments, the aerosol-generating article may comprise one or more additional components between the hollow tubular support element and the aerosol-cooling element.

By way of example, the aerosol-generating article may comprise a plug of filtration material capable of removing particulate components, gaseous components or a combination thereof. Suitable filtration materials are known in the art and include, but are not limited to: fibrous filtration materials such as, for example, cellulose acetate tow, viscose fibres, polyhydroxyalkanoates (PHA) fibres, polylactic acid (PLA) fibres and paper; adsorbents such as, for example, activated alumina, zeolites, molecular sieves and silica gel; and combinations thereof. In addition, the plug of filtration material may further comprise one or more aerosol-modifying agent. Suitable aerosol-modifying agents are known in the art and include, but are not limited to, flavourants such as, for example, menthol. A length of the plug of filtration material may be from about 4 millimetres to about 25 millimetres. Preferably, a length of the plug of filtration material is at least about 6 millimetres, more preferably at least about 8 millimetres. A length of the plug of filtration material is preferably less than or equal to about 25 millimetres, more preferably less than or equal to about 20 millimetres, even more preferably less than or equal to about 15 millimetres. In particularly preferred embodiments, a length of the plug of filtration material is less than or equal to about 10 millimetres. In an exemplary embodiment, a length of the plug of filtration material is about 5 millimetres. In another exemplary embodiment, a length of the mouthpiece is about 7 millimetres.

The aerosol-cooling element comprises a hollow tubular segment having a transverse wall at a location between an upstream end and a downstream end of the hollow tubular segment. A substantially cylindrical lumen internally defined by the hollow tubular segment is divided by the transverse wall into two spaces, namely a first cavity upstream of the transverse wall and a second cavity downstream of the transverse wall. The transverse wall comprises one or more openings extending through the transverse wall, such that a fluid communication is established via the one or more openings between the first cavity and the second cavity.

Without wishing to be bound by theory, it is understood that the upstream cavity of the aerosol-cooling element may allow air and the aerosol volatilised species drawn through the article to concentrate around the one or more openings in the transverse wall before being drawn further downstream through the one or more openings. The number, shape and size of the openings provided in the transverse wall may be selected in order to adjust an RTD of the aerosol-cooling element, as well as an RTD of the aerosol-generating article. Further, the number, shape and size of the openings may be selected in order to favour homogenisation of the air and aerosol volatilised species, as well as to increase the turbulence of their flow.

The aerosol-cooling element may be made of a material having a relatively high heat capacity, such that the aerosol-cooling element is capable of absorbing the thermal energy carried by the aerosol flowing through the article without this causing a major increase in the temperature of the aerosol-cooling element. By way of example, the aerosol-cooling element may be made of a cellulose-based compound, including a thermoplastic paper compound. By way of another example, the aerosol-cooling element may be made of polylactic acid (PLA) or a polyhydroxyalkanoate (PHA).

In some embodiments, the transverse wall has a single opening, more preferably a substantially central single opening. The central opening preferably has an equivalent diameter of at least about 0.2 millimetres. More preferably, the central opening has an equivalent diameter of at least about 0.3 millimetres.

The central opening preferably has an equivalent diameter of less than or equal to about 0.8 millimetres. More preferably, the central opening has an equivalent diameter of less than or equal to about 0.6 millimetres.

In some preferred embodiments, the central opening has an equivalent diameter from about 0.2 millimetres to about 0.8 millimetres, more preferably from 0.2 millimetres to about 0.6 millimetres. In other embodiments, the central opening preferably has an equivalent diameter from about 0.3 millimetres to about 0.8 millimetres, more preferably from about 0.3 millimetres to about 0.6 millimetres.

In other embodiments, the transverse wall has a plurality of openings. Preferably, the transverse wall has a plurality of substantially equally circumferentially spaced apart openings. For example, four, six, eight, ten, twelve substantially equally circumferentially spaced apart openings may be provided in the transverse wall.

In these embodiments, each opening preferably has an equivalent diameter of at least about 0.1 millimetres. More preferably, each opening has an equivalent diameter of at least about 0.2 millimetres. In these embodiments, each opening preferably has an equivalent diameter of at less than or equal to about 0.7 millimetres. More preferably, each opening has an equivalent diameter of less than or equal to about 0.5 millimetres. In preferred embodiments, each opening has an equivalent diameter from about 0.1 millimetres to about 0.7 millimetres or from about 0.1 millimetres to about 0.5 millimetres, more preferably from about 0.2 millimetres to about 0.7 millimetres or from about 0.2 millimetres to about 0.5 millimetres.

In some embodiments, the plurality of openings may all be arranged at the same radial distance from a longitudinal axis of the aerosol-cooling element. In other embodiments, the plurality of openings may comprise sub-sets of openings, the openings in each sub-sect being arranged at a different radial distance from a longitudinal axis of the aerosol-cooling element.

In particularly preferred embodiments, the transverse wall may comprise a first sub-set of substantially equally circumferentially spaced apart openings (for example, a sub-set of four openings) at a first radial distance from the longitudinal axis of the aerosol-cooling element and a second sub-set of substantially equally circumferentially spaced apart openings (for example, a sub-set of six openings) at a second radial distance from the longitudinal axis of the aerosol-cooling element, the second radial distance being greater that the first radial distance. This may enable a particularly homogenous distribution of the flow of air and volatilised aerosol species through the aerosol-cooling element.

In another embodiment, the transverse wall has a plurality of substantially radial slits extending from a centre of the transverse wall over a length less than a radius of the transverse wall. As used herein, the expression “substantially radial” is used to describe a slit extending from a centre of the transverse wall substantially along a radius of the aerosol-generating article. A length of the radial slit is less than a radius of the hollow tubular segment. In other words, a radial slit extends from the centre of the transverse wall to an intermediate position between the centre of the transverse wall and the peripheral wall of the hollow tubular segment.

A cross-sectional shape of the slits may be substantially rectangular or triangular. By way of example, the transverse wall may comprise three, four, five, six, eight, ten, or twelve substantially radial slits. Thus, when seen from an end of the aerosol-cooling element, the plurality of substantially radial slits may appear to define a star-shaped opening or an asterisk-shape opening in the transverse wall.

A thickness of the transverse wall as measured along the longitudinal axis of the article may be substantially constant. Alternatively, a thickness of the transverse wall varies radially and is maximum at the periphery of the transverse wall. In some embodiments, the transverse wall is shaped such as to define substantially tapered or chamfered or truncated-cone-shaped portions of the upstream cavity and the downstream cavity adjacent the transverse wall. Thus, an internal diameter of the hollow tubular segment tapers to some extent towards the transverse wall. This may advantageously facilitate concentrating the gaseous flow at the core of the aerosol-cooling element, such that the air and volatilised aerosol species are gradually directed towards the one or more openings in the transverse wall.

A length of the aerosol-cooling element may be from about 5 millimetres to about 35 millimetres. In some embodiments, a length of the aerosol-cooling element is from about 5 millimetres to about 25 millimetres or from about 5 millimetres to about 20 millimetres or from about 5 millimetres to about 19 millimetres.

Preferably, a length of the aerosol-cooling element is at least about 8 millimetres. More preferably, a length of the aerosol-cooling element is at least about 9 millimetres. A length of the aerosol-cooling element is preferably less than or equal to about 30 millimetres. More preferably, a length of the aerosol-cooling element is less than or equal to about 25 millimetres. Even more preferably, a length of the aerosol-cooling element is less than or equal to about 20 millimetres. In particularly preferred embodiments, a length of the aerosol-cooling element is less than or equal to 19 millimetres.

In preferred embodiments, a length of the aerosol cooling element is from about 8 millimetres to about 30 millimetres or from about 8 millimetres to about 25 millimetres or from about 8 millimetres to about 20 millimetres or from about 8 millimetres to about 19 millimetres, more preferably from about 9 millimetres to about 30 millimetres or from about 9 millimetres to about 25 millimetres or from about 9 millimetres to about 20 millimetres or from about 9 millimetres to about 19 millimetres.

Preferably a length of the first cavity is less than a length of the second cavity.

In preferred embodiments, a ratio between a length of the first cavity and a length of the second cavity is at least about 0.15. More preferably, a ratio between a length of the first cavity and a length of the second cavity is at least about 0.20. Even more preferably, a ratio between a length of the first cavity and a length of the second cavity is at least about 0.25. In particularly preferred embodiments, a ratio between a length of the first cavity and a length of the second cavity is at least about 0.33.

Preferably, a ratio between a length of the first cavity and a length of the second cavity is less than or equal to about 0.95. More preferably, a ratio between a length of the first cavity and a length of the second cavity is less than or equal to about 0.9. Even more preferably, a ratio between a length of the first cavity and a length of the second cavity is less than or equal to about 0.8.

In some embodiments, a ratio between a length of the first cavity and a length of the second cavity is from about 0.15 to about 0.95 or from about 0.15 to about 0.9 or from about 0.15 to about 0.8. In other embodiments, a ratio between a length of the first cavity and a length of the second cavity is from about 0.20 to about 0.95 or from about 0.20 to about 0.9 or from about 0.20 to about 0.8. In further embodiments, a ratio between a length of the first cavity and a length of the second cavity is from about 0.25 to about 0.95 or from about 0.25 to about 0.9 or from about 0.25 to about 0.8. In some other embodiments, a ratio between a length of the first cavity and a length of the second cavity is from about 0.33 to about 0.95 or from about 0.33 to about 0.9 or from about 0.33 to about 0.8.

In particularly preferred embodiments, a ratio between a length of the first cavity and a length of the second cavity is from about 0.15 to about 0.95, more preferably from about 0.2 to about 0.9, even more preferably from about 0.25 to about 0.8.

In a preferred embodiment, a ratio between a length of the first cavity and a length of the second cavity is about 0.72. In another embodiment, a ratio between a length of the first cavity and a length of the second cavity is about 0.8.

Preferably, a length of the first cavity is at least about 3 millimetres. More preferably, a length of the first cavity is at least about 4 millimetres. Even more preferably, a length of the first cavity is at least about 5 millimetres. A length of the first cavity is preferably less than or equal to about 13 millimetres. More preferably, a length of the second cavity is less than or equal to about 8 millimetres. Even more preferably, a length of the first cavity is less than or equal to 7 millimetres.

In some embodiments, a length of the first cavity is from about 3 millimetres to about 13 millimetres or from about 3 millimetres to about 8 millimetres or from about 3 millimetres to about 7 millimetres. In other embodiments, a length of the first cavity is from about 4 millimetres to about 13 millimetres or from about 4 millimetres to about 8 millimetres or from about 4 millimetres to about 7 millimetres. In further embodiments, a length of the first cavity is from about 5 millimetres to about 13 millimetres or from about 5 millimetres to about 8 millimetres or from about 5 millimetres to about 7 millimetres.

In some preferred embodiments, a length of the first cavity is from about 3 millimetres to about 13 millimetres, more preferably from about 4 millimetres to about 8 millimetres, even more preferably from about 5 millimetres to about 7 millimetres.

Preferably, a length of the second cavity is at least about 4 millimetres. More preferably, a length of the second cavity is at least about 5 millimetres. Even more preferably, a length of the second cavity is at least about 6 millimetres. A length of the second cavity is preferably less than or equal to about 17 millimetres. More preferably, a length of the second cavity is less than or equal to about 11 millimetres. Even more preferably, a length of the second cavity is less than or equal to 10 millimetres.

In some embodiments, a length of the second cavity is from about 4 millimetres to about 17 millimetres or from about 4 millimetres to about 11 millimetres or from about 4 millimetres to about 10 millimetres. In other embodiments, a length of the second cavity is from about 5 millimetres to about 17 millimetres or from about 5 millimetres to about 11 millimetres or from about 5 millimetres to about 10 millimetres. In further embodiments, a length of the second cavity is from about 6 millimetres to about 17 millimetres or from about 6 millimetres to about 11 millimetres or from about 6 millimetres to about 10 millimetres.

In some preferred embodiments, a length of the second cavity is from about 4 millimetres to about 17 millimetres, more preferably from about 5 millimetres to about 11 millimetres, even more preferably from about 6 millimetres to about 10 millimetres.

Preferably, a thickness of a peripheral wall of the hollow tubular segment is at least about 0.2 millimetres. More preferably, a thickness of the peripheral wall of the hollow tubular segment is at least about 0.5 millimetres. Even more preferably a thickness of the peripheral wall of the hollow tubular segment is at least about 1 millimetre. A thickness of the peripheral wall of the hollow tubular segment is preferably less than or equal to 3.5 millimetres. More preferably, a thickness of the peripheral wall of the hollow tubular segment is less than or equal to 3 millimetres. Even more preferably, a thickness of the peripheral wall of the hollow tubular segment is less than or equal to about 2.5 millimetres.

In some embodiments, a thickness of a peripheral wall of the hollow tubular segment is from about 0.2 millimetres to about 3.5 millimetres or from about 0.2 millimetres to about 3 millimetres or from about 0.2 millimetres to about 2.5 millimetres. In other embodiments, a thickness of a peripheral wall of the hollow tubular segment is from about 0.5 millimetres to about 3.5 millimetres or from about 0.5 millimetres to about 3 millimetres or from about 0.5 millimetres to about 2.5 millimetres. In further embodiments, a thickness of a peripheral wall of the hollow tubular segment is from about 1 millimetre to about 3.5 millimetres or from about 1 millimetre to about 3 millimetres or from about 1 millimetre to about 2.5 millimetres.

In some preferred embodiments, a thickness of the peripheral wall of the hollow tubular segment is from about 0.2 millimetres to about 3.5 millimetres, more preferably from about 0.5 millimetres to about 3 millimetres, even more preferably from about 1 millimetre to about 2.5 millimetres.

Preferably, an outer diameter of the hollow tubular segment is at least about 3 millimetres. More preferably, an outer diameter of the hollow tubular segment is at least about 4 millimetres. Even more preferably, an outer diameter of the hollow tubular segment is at least about 5 millimetres. An outer diameter of the hollow tubular segment is preferably less than or equal to about 13 millimetres. More preferably, an outer diameter of the hollow tubular segment is less than or equal to about 10 millimetres. Even more preferably, an outer diameter of the hollow tubular segment is less than or equal to about 8 millimetres.

In some embodiments, an outer diameter of the hollow tubular segment is from about 3 millimetres to about 13 millimetres or from about 3 millimetres to about 10 millimetres or from about 3 millimetres to about 8 millimetres. In other embodiments, an outer diameter of the hollow tubular segment is from about 4 millimetres to about 13 millimetres or from about 4 millimetres to about 10 millimetres or from about 4 millimetres to about 8 millimetres. In further embodiments, an outer diameter of the hollow tubular segment is from about 5 millimetres to about 13 millimetres or from about 5 millimetres to about 10 millimetres or from about 5 millimetres to about 8 millimetres.

In preferred embodiments, an outer diameter of the hollow tubular segment is from about 3 millimetres to about 13 millimetres, more preferably from about 4 millimetres to about 10 millimetres, even more preferably from about 5 millimetres to about 8 millimetres. In some embodiments, an outer diameter of the hollow tubular segment is from about 4 millimetres to about 8 millimetres.

Preferably, an inner diameter of the hollow tubular segment is at least about 2 millimetres. More preferably, an inner diameter of the hollow tubular segment is at least about 3 millimetres. Even more preferably, an inner diameter of the hollow tubular segment is at least about 4 millimetres. An inner diameter of the hollow tubular segment is preferably less than or equal to about 10 millimetres. More preferably, an inner diameter of the hollow tubular segment is less than or equal to about 7.5 millimetres. Even more preferably, an inner diameter of the hollow tubular segment is less than or equal to about 6 millimetres.

In some embodiments, an inner diameter of the hollow tubular segment is from about 2 millimetres to about 10 millimetres or from about 2 millimetres to about 7.5 millimetres or from about 2 millimetres to about 6 millimetres. In other embodiments, an inner diameter of the hollow tubular segment is from about 3 millimetres to about 10 millimetres or from about 3 millimetres to about 7.5 millimetres or from about 3 millimetres to about 6 millimetres. In further embodiments, an inner diameter of the hollow tubular segment is from about 4 millimetres to about 10 millimetres or from about 4 millimetres to about 7.5 millimetres or from about 4 millimetres to about 6 millimetres.

In preferred embodiments, an inner diameter of the hollow tubular segment is from about 2 millimetres to about 10 millimetres, more preferably from about 3 millimetres to about 7.5 millimetres, even more preferably from about 4 millimetres to about 6 millimetres. In some embodiments, an inner diameter of the hollow tubular segment is from about 3 millimetres to about 7.5 millimetres.

An overall length of the aerosol-generating article is preferably at least about 35 millimetres. More preferably, an overall length of the aerosol-generating article is at least about 40 millimetres. Even more preferably, an overall length of the aerosol-generating article is at least about 45 millimetres. In addition, or as an alternative, an overall length of the aerosol-generating article is preferably less than or equal to about 100 millimetres. More preferably, an overall length of the aerosol-generating article is less than or equal to about 80 millimetres. Even more preferably, an overall length of the aerosol-generating article is less than or equal to about 75 millimetres. Most preferably, an overall length of the aerosol-generating article is less than or equal to about 70 millimetres.

In some embodiments, an overall length of the aerosol-generating article is from about 35 millimetres to about 100 millimetres or from about 35 millimetres to about 80 millimetres or from about 35 millimetres to about 75 millimetres or from about 35 millimetres to about 70 millimetres. In other embodiments, an overall length of the aerosol-generating article is from about 40 millimetres to about 100 millimetres or from about 40 millimetres to about 80 millimetres or from about 40 millimetres to about 75 millimetres or from about 40 millimetres to about 70 millimetres. In further embodiments, an overall length of the aerosol-generating article is from about 45 millimetres to about 100 millimetres or from about 45 millimetres to about 80 millimetres or from about 45 millimetres to about 75 millimetres or from about 45 millimetres to about 70 millimetres.

In particularly preferred embodiments, an overall length of the aerosol-generating article is from about 35 millimetres to about 80 millimetres, more preferably from about 40 millimetres to about 75 millimetres, even more preferably from about 45 millimetres to about 70 millimetres.

As described briefly above, the aerosol-generating article may comprise an additional component between the hollow tubular support element and the aerosol-cooling element, In some embodiments, the additional component may be a further aerosol-cooling element (also referred herein as a ‘secondary’ aerosol-cooling element) adapted to initiate cooling of the gaseous flow incoming from the aerosol-generating substrate so as to facilitate condensation of the compounds released from the substrate such that they condense to form the aerosol. In some embodiments, the secondary aerosol-cooling element may be in the form of a gathered, optionally crimped sheet of a polymeric material, such as polylactic acid (PLA), that defines a plurality of longitudinally extending channels. In practice, a sheet of PLA may be ‘crimped’ to form substantially parallel ridges or corrugations. Then, the crimped PLA sheet may be gathered, convoluted, pleated or folded, or otherwise compressed or constricted substantially transversely to the longitudinal axis such that the substantially parallel ridges or corrugations extend in the longitudinal direction. Without wishing to be bound by theory, one such gathered, crimped sheet of polymeric material may act substantially as a heat exchanger.

Preferably, a length of the further aerosol-cooling element is at least about 4 millimetres. More preferably, a length of the further aerosol-cooling element is at least about 6 millimetres. Even more preferably, a length of the further aerosol-cooling element is at least about 9 millimetres. A length of the further aerosol-cooling element is preferably less than or equal to about 25 millimetres. More preferably, a length of the further aerosol-cooling element is preferably less than or equal to about 20 millimetres. Even more preferably, length of the further aerosol-cooling element is preferably less than or equal to about 15 millimetres.

In some embodiments, a length of the further aerosol-cooling element is from about 4 millimetres to about 25 millimetres or from about 4 millimetres to about 20 millimetres or from about 4 millimetres to about 15 millimetres. In other embodiments, a length of the further aerosol-cooling element is from about 6 millimetres to about 25 millimetres or from about 6 millimetres to about 20 millimetres or from about 6 millimetres to about 15 millimetres. In further embodiments, a length of the further aerosol-cooling element is from about 9 millimetres to about 25 millimetres or from about 9 millimetres to about 20 millimetres or from about 9 millimetres to about 15 millimetres.

In some preferred embodiments, a length of the further aerosol-cooling element is from about 4 millimetres to about 25 millimetres, more preferably from about 6 millimetres to about 20 millimetres, from about 9 millimetres to about 15 millimetres.

Components of an aerosol-generating article in accordance with the invention may be individually circumscribed by a wrapper. The wrapper may be formed of a porous or non-porous sheet material. The wrapper may be formed of any suitable material or combination of materials. Preferably, the wrapper is a paper wrapper. Two or more components may, however, also be circumscribed by a same wrapper. Further, the rod of aerosol-generating substrate and the other components are typically assembled within a single wrapper. For example, in an embodiment, the aerosol-generating article comprises, in linear sequential arrangement, a rod of aerosol-generating substrate, a tubular support element, an aerosol-cooling element as described above, and an outer wrapper circumscribing the rod, the support element and the aerosol-cooling element. In another embodiment, the aerosol-generating article comprises, in linear sequential arrangement, a rod of aerosol-generating substrate, a tubular support element, a secondary aerosol-cooling element, an aerosol-cooling element as described above, and an outer wrapper circumscribing the rod, the support element and the aerosol-cooling elements.

In some embodiments, the aerosol-generating articles comprises a ventilation zone at a location along the aerosol-cooling element. Preferably, the aerosol-generating article comprises a ventilation zone at a location along the length of the aerosol-cooling element.

In some embodiments, the ventilation zone is provided at a location along the upstream cavity. Thus, a fluid communication is established between the outer environment and the upstream cavity such that, when the consumer draws upon the aerosol-generating article, some environment air is drawn into the upstream cavity through ventilation holes formed through the peripheral wall of the hollow tubular segment. This is advantageous in that by mixing environment air with the incoming flow of aerosol may lower the temperature of the aerosol and favour condensation or growth of aerosol particles or both. At the same, the flow of environment air through the peripheral wall of the aerosol-cooling element may further facilitate maintaining the temperature of the peripheral wall below the desired threshold value.

In other embodiments, the ventilation zone is provided at a location along the length of the aerosol-cooling element such that a fluid communication is established between the outer environment and the downstream cavity. In particularly preferred embodiments, the ventilation zone comprises a plurality of holes extending through the peripheral wall and the transverse wall of the aerosol-cooling element, such that slanted airflow conduits are formed that connect the outer environment with the downstream cavity. This may particularly facilitate keeping the temperature of the peripheral wall of the aerosol-cooling element below the desired threshold value, especially at locations near the transverse wall, where heat transferred is expected to be maximum.

Aerosol-generating articles as described above may be used in an electrically operated aerosol generating device as part of an aerosol-generating system in accordance with another aspect of the present invention. One such aerosol-generating system comprises an aerosol generating article as described above and an electrically operated aerosol generating device comprising a heating element and an elongate heating chamber configured to receive the aerosol generating article so that the rod of aerosol-generating substrate is heated in the heating chamber. Preferably, the heating element comprises a heater blade or a heater pin adapted to be inserted into the rod of aerosol-generating substrate when the aerosol generating article is received into the heating chamber.

The invention will now be further described with reference to the figures in which:

FIG. 1 shows a schematic side sectional view of an aerosol-generating article in accordance with a first embodiment of the invention;

FIG. 2 shows a schematic side sectional view of an aerosol-generating article in accordance with a second embodiment of the invention;

FIGS. 3, 4, 5, 6, 7 and 8 show schematic cross-sectional views of variants of the aerosol-generating article of FIG. 1 taken along the plane A-A illustrating different arrangements for the transverse wall of the aerosol-cooling element; and

FIG. 9 shows a schematic longitudinal cross-sectional view of an aerosol-generating system comprising an electrically operated aerosol-generating device and the aerosol-generating article shown in FIG. 1.

The aerosol-generating article 10 shown in FIG. 1 comprises a rod of aerosol-generating substrate 12, a tubular support element 14, and an aerosol-cooling element 16. These three elements are arranged sequentially and in coaxial alignment and are circumscribed by a wrapper 18 to form the aerosol-generating article 10. The aerosol-generating article 10 has a mouth end or downstream end 20, and an upstream end 22 located at the opposite end of the article to the mouth end 20. The aerosol-generating article 10 shown in FIG. 1 is particularly suitable for use with an electrically operated aerosol-generating device comprising a heater for heating the rod of aerosol-generating substrate.

The rod of aerosol-generating substrate 12 has a length of approximately 12 millimetres and a diameter of approximately 7 millimetres. The rod 12 is cylindrical in shape and has a substantially circular cross-section.

The tubular support element 14 is provided as a hollow tube of cellulose acetate. The tubular support element 14 has a length of approximately 8 millimetres. An external diameter of the tubular support element 14 is approximately 7 millimetres. A peripheral wall of the tubular support element 14 has a thickness of about 1.85 millimetres.

The aerosol-cooling element 16 is made of a cellulose-based, thermoplastic compound and has an overall length of about 14 millimetres. The aerosol-cooling element 16 comprises a hollow tubular segment comprising a peripheral 24 wall having a thickness of about 0.5 millimetres. Further, the hollow tubular segment comprises a transverse wall 26 at a location between an upstream end and a downstream end of the hollow tubular segment. As such, the hollow tubular segment defines a first cavity 28 upstream of the transverse wall 26 and a second cavity 30 downstream of the transverse wall 26.

An opening 32 is formed into the transverse wall 26 to establish a fluid communication between the first cavity 28 and the second cavity 30. The first, upstream cavity 28 has a length of about 6 millimetres. The second, downstream cavity 30 has a length of about 8 millimetres. Thus, a ratio between a length of the first cavity and a length of the second cavity is about 0.75.

The opening 32 is arranged at a central location in the transverse wall 26, and has an equivalent diameter of about 0.5 millimetres.

FIG. 2 illustrates another embodiment of an aerosol-generating article 50 in accordance with the present invention. The aerosol-generating article 50 is similar to the aerosol-generating article 10 of FIG. 1 and will be described in the following only insofar as it differs from the aerosol-generating article 10. Wherever possible, the same reference numerals will be used to identify components of the article that are present in both embodiments.

The aerosol-generating article 50 shown in FIG. 2 comprises a rod of aerosol-generating substrate 12, a tubular support element 14, and an aerosol-cooling element 16. Further, the aerosol-generating article 50 comprises a secondary aerosol-cooling element 40 between the tubular support element 14 and the aerosol-cooling element 16. All four elements are arranged sequentially and in coaxial alignment and are circumscribed by a wrapper 18 to form the aerosol-generating article 50. The aerosol-generating article 50 has a mouth end or downstream end 20, and an upstream end 22 located at the opposite end of the article to the mouth end 20.

The secondary aerosol-cooling element 40 comprises a gathered, crimped sheet of a PLA, that defines a plurality of longitudinally extending channels. Arrows show schematically the direction of flow of the aerosol flowing through the article. After travelling through the secondary aerosol-cooling element, the aerosol flow is concentrated through the opening 32 in the transverse wall 26 prior to being distributed more broadly into the downstream cavity 30 of the aerosol-cooling element 16 and prior to reaching the consumer's mouth.

FIGS. 3 to 8 show details of alternative embodiments of aerosol-generating articles in accordance with the invention. In particular, FIGS. 3 to 8 illustrate different arrangements for the one or more openings in the transverse wall of the aerosol-cooling element by means of cross-sectional views taken in planes corresponding to the plane X-X shown in FIGS. 1 and 2.

FIGS. 3 to 5 show embodiments wherein the transverse wall comprises a plurality of substantially equally circumferentially spaced apart openings 34 on top of a central opening. In the embodiment of FIG. 3 the plurality of openings 34 are provided as two sub-sets of openings provided at different radial distances from the central opening (that is, from a longitudinal axis of the article). In the embodiments of FIGS. 4 and 5, the transverse wall comprises only a set of circumferentially aligned openings 34. In the embodiments of FIGS. 6 to 8, on the other hand, the transverse wall comprises a plurality of substantially radial slits 36 extending from a central position to a location between the centre and the periphery of the transverse wall. Thus, in these embodiments, a star-shaped or asterisk-shaped opening is effectively provided in the transverse wall. Without wishing to be bound by theory, it is understood that by varying the size and position of the plurality of openings 32, 34, 36 in the transverse wall 26, it is possible to adjust and tune the homogenisation and mixing of the air and airborne volatilised aerosol species prior to the aerosol being delivered to the consumer's mouth. At the same time, by concentrating the flow of aerosol at locations more or less close to the longitudinal axis of the aerosol-generating article, it is possible to favour transfer of heat from the aerosol to selected portions of the transverse wall over transfer of heat from the aerosol to the peripheral wall of the aerosol-cooling element. Thus, it is advantageously easy to ensure that the surfaces of the article that, during use, come into contact with the consumer's mouth do not reach temperatures above a given threshold.

FIG. 9 shows a portion of an electrically operated aerosol-generating system 200 that utilises a heater blade 210 to heat the rod of aerosol-generating substrate 12 of the aerosol-generating article 10 shown in FIG. 1. The heater blade 210 is mounted within an aerosol-generating article chamber within a housing of an electrically operated aerosol-generating device 212. The aerosol-generating device 212 defines a plurality of air holes 214 for allowing air to flow to the aerosol-generating article 10, as illustrated by the arrows in FIG. 9. The aerosol-generating device 212 comprises a power supply and electronics, which are not shown in FIG. 9.

The aerosol-generating article 10 shown in FIG. 1 is designed to engage with the aerosol-generating device 212 shown in FIG. 9 in order to be consumed.

The user inserts the aerosol-generating article 10 into the aerosol-generating device 212 so that the heater blade 210 is inserted into the rod of aerosol-generating substrate 12. The aerosol-cooling element 16 projects outwards from the mouth end of the device 212. Once the aerosol-generating article 10 is engaged with the aerosol-generating device 212, the user draws on the aerosol-cooling element 16 defining a mouthpiece of the aerosol-generating article 10 and the rod of aerosol-generating substrate 12 is heated by the heater blade 210 to a temperature sufficient to generate an aerosol from the rod of aerosol-generating substrate 12. The aerosol is drawn through the aerosol-cooling element 16 and into the user's mouth.

It will be appreciated that the aerosol-generating article 10 shown in FIG. 1 may also be suitable for use with other types of aerosol-generating devices. 

1.-15. (canceled)
 16. An aerosol-generating article for producing an aerosol upon heating, the aerosol-generating article comprising: a rod of aerosol-generating substrate comprising an aerosol former, the aerosol-generating substrate having an aerosol former content of greater than 10 percent on a dry weight basis; a hollow tubular support element positioned immediately downstream of the rod of aerosol-generating substrate; an aerosol-cooling element downstream of the hollow tubular support element, the aerosol-cooling element extending all the way to a downstream end of the aerosol-generating article, wherein the aerosol-cooling element comprises a hollow tubular segment having a transverse wall at a location between an upstream end and a downstream end of the hollow tubular segment, such that the hollow tubular segment defines a first cavity upstream of the transverse wall and a second cavity downstream of the transverse wall, and wherein the transverse wall comprises one or more openings establishing a fluid communication between the first cavity and the second cavity.
 17. The aerosol-generating article according to claim 16, wherein the transverse wall has a single substantially central opening provided therein and having an equivalent diameter of between 0.3 mm and 0.6 mm.
 18. The aerosol-generating article according to claim 16, wherein the transverse wall has a plurality of substantially equally circumferentially spaced apart openings, each opening having an equivalent diameter of between 0.1 mm and 0.5 mm.
 19. The aerosol-generating article according to claim 16, wherein the transverse wall has a plurality of substantially radial slits extending from a center of the transverse wall over a length less than a radius of the transverse wall.
 20. The aerosol-generating article according to claim 16, wherein a length of the aerosol-cooling element is at least about 5 mm.
 21. The aerosol-generating article according to claim 16, wherein a length of the aerosol-cooling element is less than about 20 mm.
 22. The aerosol-generating article according to claim 16, wherein a length of the first cavity is less than a length of the second cavity.
 23. The aerosol-generating article according to claim 16, wherein a ratio between a length of the first cavity and a length of the second cavity is from about 0.15 to about 0.8.
 24. The aerosol-generating article according to claim 16, wherein a length of the first cavity is at least about 3 mm.
 25. The aerosol-generating article according to claim 16, wherein a length of the first cavity is less than about 13 mm.
 26. The aerosol-generating article according to claim 16, wherein a length of the second cavity is at least about 5 mm.
 27. The aerosol-generating article according to claim 16, wherein a length of the second cavity is less than about 17 mm.
 28. The aerosol-generating article according to claim 16, wherein a thickness of a peripheral wall of the hollow tubular segment is at least about 2 mm.
 29. The aerosol-generating article according to claim 16, wherein an outer diameter of the hollow tubular segment is at least about 3 mm.
 30. The aerosol-generating article according to claim 16, further comprising a further aerosol-cooling element between the tubular support element and the aerosol-cooling element, wherein a length of the first aerosol-cooling element is from about 4 mm to about 20 mm. 